/**
 * L13 互动课 · 共用组件（按钮、语料、时间轴、测验等）
 * 各页在 l13-lesson-shell.css 之后引入本文件
 */
#l13-book .rule-box {
  padding: 0.65rem 0.75rem;
  border-radius: 12px;
  font-weight: 700;
  font-size: 0.92rem;
  margin: 0.45rem 0;
  line-height: 1.45;
}
#l13-book .rule-box.violet {
  background: var(--violet-bg, #ede9fe);
  border-left: 5px solid var(--violet, #7c3aed);
  color: #4c1d95;
}
#l13-book .rule-box.amber {
  background: #fffbeb;
  border-left: 5px solid #d97706;
  color: #92400e;
}
#l13-book .rule-box.teal {
  background: #f0fdfa;
  border-left: 5px solid #0d9488;
  color: #134e4a;
}

#l13-book .zh-hint {
  font-size: 0.86rem;
  color: #6d4c41;
  font-weight: 700;
  margin: 0.2rem 0 0.45rem;
  line-height: 1.45;
}
#l13-book .en-line {
  font-size: var(--lesson-fs-en-line, 1.12rem);
  font-weight: 800;
  color: #1e293b;
  margin: 0.4rem 0;
  line-height: 1.5;
}

#l13-book .hl-had {
  background: #ede9fe;
  color: #6d28d9;
  padding: 0 0.12rem;
  border-radius: 4px;
  font-weight: 900;
}
#l13-book .hl-past {
  background: #dbeafe;
  color: #1d4ed8;
  padding: 0 0.12rem;
  border-radius: 4px;
  font-weight: 900;
}
#l13-book .hl-pp {
  background: #ccfbf1;
  color: #0f766e;
  padding: 0 0.12rem;
  border-radius: 4px;
  font-weight: 900;
}

#l13-book .tier-label {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 900;
  padding: 0.1rem 0.42rem;
  border-radius: 6px;
  margin-right: 0.35rem;
  background: var(--violet-bg, #ede9fe);
  color: var(--violet-ink, #5b21b6);
}

#l13-book .btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin: 0.5rem 0;
  align-items: center;
}
#l13-book .btn {
  min-height: 44px;
  padding: 0.45rem 1rem;
  border-radius: 12px;
  border: 2px solid var(--edge, #5d4037);
  background: linear-gradient(180deg, #fff, #f8fafc);
  font-weight: 800;
  cursor: pointer;
  font-size: 0.88rem;
  touch-action: manipulation;
  font-family: inherit;
  box-shadow: 0 2px 0 rgba(93, 64, 55, 0.1);
  transition: filter 0.15s ease, transform 0.1s ease;
}
#l13-book .btn:hover:not(:disabled) {
  filter: brightness(1.03);
}
#l13-book .btn:active:not(:disabled) {
  transform: translateY(1px);
}
#l13-book .btn.teal {
  background: linear-gradient(135deg, #2dd4bf, #0d9488);
  color: #fff;
  border-color: #0f766e;
  box-shadow: 0 3px 0 rgba(15, 118, 110, 0.3);
}
#l13-book .btn.violet {
  background: linear-gradient(135deg, #a78bfa, #7c3aed);
  color: #fff;
  border-color: #5b21b6;
  box-shadow: 0 3px 0 rgba(91, 33, 182, 0.28);
}
#l13-book .btn.ghost {
  background: #f8fafc;
  color: #334155;
  border-color: #cbd5e1;
  box-shadow: 0 2px 0 rgba(148, 163, 184, 0.2);
}
#l13-book .btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
  box-shadow: none;
}
#l13-book a.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
}

/* 语料库 */
#l13-book .corpus-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin-bottom: 0.5rem;
  flex-shrink: 0;
}
#l13-book .corpus-tab {
  min-height: 40px;
  padding: 0.35rem 0.75rem;
  border-radius: 999px;
  border: 2px solid var(--edge, #5d4037);
  background: #fff;
  font-weight: 800;
  font-size: 0.8rem;
  cursor: pointer;
  font-family: inherit;
}
#l13-book .corpus-tab.active {
  background: var(--violet-bg, #ede9fe);
  border-color: var(--violet, #7c3aed);
  color: var(--violet-ink, #5b21b6);
}
#l13-book .corpus-list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
#l13-book .corpus-list--preview {
  flex: 1 1 auto;
  min-height: 0;
  overflow-y: auto;
  max-height: min(52vh, 440px);
  padding-right: 0.15rem;
}
#l13-book .panel-corpus-preview {
  display: flex;
  flex-direction: column;
  min-height: min(320px, 48vh);
}
#l13-book .corpus-item {
  padding: 0.6rem 0.65rem;
  border-radius: 12px;
  border: 2px solid #e2e8f0;
  background: #fafafa;
}
#l13-book .corpus-item .tag {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 900;
  padding: 0.1rem 0.45rem;
  border-radius: 6px;
  background: #f3e8ff;
  color: #6d28d9;
  margin-bottom: 0.35rem;
}
#l13-book .corpus-item .en {
  font-weight: 800;
  font-size: 0.9rem;
  line-height: 1.45;
  color: #1e293b;
}
#l13-book .corpus-item .zh {
  font-size: 0.82rem;
  font-weight: 700;
  color: #64748b;
  margin-top: 0.2rem;
}
#l13-book .corpus-item-figs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.4rem;
  margin: 0.4rem 0;
}
@media (max-width: 520px) {
  #l13-book .corpus-item-figs {
    grid-template-columns: 1fr;
  }
}
#l13-book .corpus-fig {
  margin: 0;
  border-radius: 10px;
  overflow: hidden;
  border: 2px solid #e2e8f0;
  background: #fff;
}
#l13-book .corpus-fig img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: contain;
  display: block;
  background: linear-gradient(145deg, #f8fafc, #f1f5f9);
}
#l13-book .corpus-fig figcaption {
  font-size: 0.68rem;
  font-weight: 800;
  padding: 0.25rem 0.4rem;
  text-align: center;
  background: #f8fafc;
  color: #475569;
}

/* 时间轴拖拽 */
#l13-book .event-pool {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin: 0.45rem 0;
  padding: 0.5rem;
  border-radius: 12px;
  border: 2px dashed #c4b5fd;
  background: #faf5ff;
  min-height: 56px;
}
#l13-book .event-chip {
  flex: 1 1 min(100%, 140px);
  max-width: 100%;
  padding: 0.45rem 0.55rem;
  border-radius: 10px;
  border: 2px solid #cbd5e1;
  background: #fff;
  cursor: grab;
  touch-action: manipulation;
  line-height: 1.35;
}
#l13-book .event-chip .chip-zh {
  display: block;
  font-size: 0.78rem;
  font-weight: 800;
  color: #334155;
}
#l13-book .event-chip span[lang="en"] {
  display: block;
  font-size: 0.72rem;
  font-weight: 700;
  color: #64748b;
  margin-top: 0.15rem;
}
#l13-book .event-chip.selected {
  outline: 3px solid var(--violet, #7c3aed);
  border-color: var(--violet, #7c3aed);
}
#l13-book .event-chip.used {
  opacity: 0.45;
  pointer-events: none;
}
#l13-book .timeline-board {
  display: grid;
  gap: 0.5rem;
  margin: 0.5rem 0;
}
@media (min-width: 640px) {
  #l13-book .timeline-board {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  #l13-book .timeline-board:has(.tl-lane:nth-child(4)) {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}
#l13-book .tl-lane h4 {
  margin: 0 0 0.35rem;
  font-size: 0.78rem;
  font-weight: 900;
  color: #475569;
  text-align: center;
}
#l13-book .tl-lane.earlier h4 { color: #5b21b6; }
#l13-book .tl-lane.past h4 { color: #b91c1c; }
#l13-book .tl-lane.now h4 { color: #b45309; }
#l13-book .tl-drop {
  min-height: 76px;
  padding: 0.45rem 0.5rem;
  border-radius: 10px;
  border: 2px dashed #94a3b8;
  background: #f8fafc;
  font-size: 0.78rem;
  font-weight: 700;
  color: #94a3b8;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.2rem;
  line-height: 1.35;
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s;
}
#l13-book .tl-drop.drag-over {
  border-color: var(--violet, #7c3aed);
  background: #f5f3ff;
}
#l13-book .tl-drop.filled {
  border-style: solid;
  border-color: #cbd5e1;
  color: #1e293b;
  font-weight: 800;
}
#l13-book .tl-drop.ok {
  border-color: #047857;
  background: #ecfdf5;
}
#l13-book .tl-drop.bad {
  border-color: #b91c1c;
  background: #fef2f2;
}
#l13-book .tl-fb {
  margin: 0.35rem 0;
  padding: 0.5rem 0.65rem;
  border-radius: 10px;
  font-weight: 800;
  font-size: 0.86rem;
  background: #ecfdf5;
  color: #047857;
}
#l13-book .tl-fb.warn {
  background: #fffbeb;
  color: #92400e;
}

/* 测验 */
#l13-book .quiz-item {
  padding: 0.65rem;
  margin: 0.45rem 0;
  border-radius: 12px;
  border: 2px solid #e2e8f0;
  background: #fff;
}
#l13-book .quiz-item.done {
  border-color: #047857;
  background: #ecfdf5;
}
#l13-book .opt-row {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  margin-top: 0.4rem;
}
#l13-book .opt-row button {
  min-height: 44px;
  padding: 0.45rem 0.65rem;
  border-radius: 10px;
  border: 2px solid #cbd5e1;
  background: #fff;
  font-weight: 800;
  font-size: 0.84rem;
  cursor: pointer;
  text-align: left;
  font-family: inherit;
  line-height: 1.35;
}
#l13-book .opt-row button.ok {
  background: #ecfdf5;
  border-color: #047857;
}
#l13-book .opt-row button.bad {
  background: #fef2f2;
  border-color: #b91c1c;
}
#l13-book .fb {
  margin-top: 0.35rem;
  font-size: 0.82rem;
  font-weight: 700;
  color: #475569;
}

/* 归纳 / 对比 / 路线图 */
#l13-book .summary-pick {
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
}
#l13-book .summary-pick label {
  display: flex;
  align-items: flex-start;
  gap: 0.45rem;
  padding: 0.55rem 0.65rem;
  border-radius: 12px;
  border: 2px solid #e2e8f0;
  background: #fff;
  font-weight: 700;
  font-size: 0.88rem;
  line-height: 1.4;
  cursor: pointer;
}
#l13-book .summary-pick input {
  margin-top: 0.2rem;
  flex-shrink: 0;
}
#l13-book .contrast-pair {
  padding: 0.65rem;
  margin: 0.45rem 0;
  border-radius: 12px;
  border: 2px solid #e2e8f0;
  background: #fafafa;
}
#l13-book .contrast-pair .line {
  margin: 0.25rem 0;
  font-weight: 800;
  font-size: 0.88rem;
  line-height: 1.45;
}
#l13-book .roadmap {
  margin: 0;
  padding-left: 1.25rem;
  font-weight: 700;
  line-height: 1.65;
}
#l13-book .roadmap a {
  color: var(--l13-accent-ink, #0f766e);
  font-weight: 800;
}
#l13-book .roadmap li {
  margin: 0.35rem 0;
}

/* 故事导入屏 */
#l13-book .panel-story-intro {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
  align-items: stretch;
}
#l13-book .story-purpose-lead {
  margin: 0;
  font-weight: 800;
  font-size: 0.92rem;
  line-height: 1.5;
  color: #334155;
}
#l13-book .scene-frame--story {
  max-height: min(58vh, 480px);
}